The field of this invention is simulated environmental testing and more particularly relates to a test chamber which is capable of simulating a broad spectrum of environmental conditions to which equipment might be subjected in field use. The value and need for such test chambers is obvious. Prototypes of new designs of all sorts of military equipment, for example military vehicles, electronic equipment, clothing, engineering structural equipment, medical equipment, ammunition, and even food supplies must be tested in many types of environments in which the equipment may be stored or required to operate, from the snow covered mountains of Alaska to tropical jungles.
Prior art test chambers of this type have been equipped to provide control of humidity only above 32.degree. F. Dew or frost was never formed in such chambers in a controllable manner. It could have been formed if a cold object were placed in a warmer and humid chamber, however this method of dew or frost formation is inconvenient and more important, not subject to precise controls.
The chamber of the present invention is a novel and versatile one which provides controllable dew and frost formation by means of a chilled black body heat absorber which simulates the radiative cooling of outdoor objects which takes place on clear nights. By controlling the temperature of the black body heat absorber and the temperature and humidity of the air in the chamber, any degree of dew or frost buildup can be induced on test objects in the chamber.